[0001] The present invention relates to a polypeptide according to claim 1, a composition
of matter according to claim 2 and claim 4, a matrix according to claim 8, a hydrogel
according to claim 9, a method of generating a hydrogel according to claim 10, a method
of inducing ex vivo formation of a tissue according to claim 15, a use of the matrix
according to claim 13.
[0002] The present invention, in some embodiments thereof, relates to compositions comprising
a novel laminin polypeptide and, more particularly, but not exclusively, to matrices
and hydrogels comprising same and methods of using same.
[0003] Hydrated gels (hydrogels) are viscous, semisolid entities at physiological temperatures
and pH which can be used for tissue engineering, regenerative medicine and as biomaterials.
For example, hydrogels were prepared from polysaccharides (Coviello et al, 2007) such
as hyaluronic acid (e.g., using hybrid combinations of hyaluronic acid with calcium
phosphate, chitosan, gelatin or alginate) or chitosan (e.g., chitosan with laminin
peptides; Suzuki et. al., 2003; Itoh et. al., 2005; Matzuda et. aL, 2005, Ho et. al.,
2005) as well as from synthetic materials such as Poly(2-hydroxyethyl methacrylate).
Hyaluronic acid-based hydrogels provide a growth supportive milieu for cells and tissues
such as for nerve regeneration (Suzuki et. al., 2003; Itoh et. al., 2005), while guiding
migration and regeneration of nutritional-trophic and anti oxidative agents.
[0004] Laminins are basement membrane glycoproteins which function as adhesive molecules,
mediating and interacting with cytoskeleton's bound integrins, cadherins, cell adhesive
molecules (CAMs) and extracellular matrix (ECM) constituents and support cell migration,
attachment, proliferation, differentiation and survival. Hyaluronic acid-based hydrogels
which were modified with laminin were shown to promote neurite extension (Hou et.
al., 2005). Certain laminin sequence repeats were found to have a biological activity
on cell surface receptors. These include IKVAV (SEQ ID NO:1) and YIGSR (SEQ ID NO:2)
which serve as guiding tracks for migration, regeneration and gmwth (Tashiro et. al.,
1989; Powell and Kleinman, 1997; Niece et. al., 2003; Hallmann et. al., 2005).
[0005] The primary defense mechanism against oxidative stress is the enzyme superoxide dismutase
(SOD) which catalyzes the dismutation of superoxide anion free radical (O
2-) to hydrogen peroxide (H
2O
2) and oxygen (O
2). Hydrogels which include SOD from bovine erythrocytes conjugated to sodium hyalutonate
were found to be non-immunogenic in mice and exhibited much higher anti-inflammatory
activities than HA or SOD alone (Sekurai et. al., 1997). In addition, SOD was found
to inhibit not only reactive oxygen species (ROS) induction but also HA depolymerization
which is caused by mechanical stress (Yamazaki et. al., 2003).
[0007] The polypeptide of the present invention is defined in claim 1, the composition of
matter of the present invention is defined in claim 2 and claim 4, the matrix of the
present invention is defined in claim 8, the hydrogel of the present Invention is
defined In claim 9, the method of generating a hydrogel of the present invention is
defined in claim 10, the method of inducing ex vivo formation of a tissue of the present
invention is defined In claim 15, the use of the matrix of the present Invention is
defined In claim 13.
[0008] According to an aspect of some embodiments of the present invention there is provided
a polypeptide comprising the amino acid sequence set forth by SEQ ID NO:3.
[0009] According to an aspect of some embodiments of the present invention there is provided
a composition-of-matter comprising a polysaccharide and the polypeptide of the invention.
[0010] According to an aspect of some embodiments of the present invention there is provided
a composition-of-matter comprising hyaluronic acid, a laminin polypeptide and an antioxidant.
[0011] According to an aspect of some embodiments of the present invention there is provided
a composition-of-matter comprising hyaluronic acid, superoxide dismutase (SOD) and
the polypeptide of the invention.
[0012] According to an aspect of some embodiments of the present invention there is provided
a matrix comprising the composition-of-matter of the invention.
[0013] According to an aspect of some embodiments of the present invention there is provided
a hydrogel comprising the composition-of-matter of the invention.
[0014] According to an aspect of some embodiments of the present invention there is provided
a method of generating a hydrogel, the method comprising suspending the composition-of-matter
of the invention in water so as to obtain a suspension which comprises at least 80
% water, thereby generating the hydrogel,
[0015] According to an aspect of some embodiments of the present invention there is provided
a method of inducing
ex vivo formation of a tissue, comprising: (a) providing the matrix or the hydrogel of the
invention, and; (ii) seeding the matrix or the hydrogel with cells in a medium suitable
for proliferation, differentiation and/or migration of the cells, thereby inducing
the formation of the tissue.
[0016] According to an aspect of some embodiments of the present invention there is provided
a method of inducing
in vivo formation of a tissue, the method comprising implanting the matrix or the hydrogel
of the invention in a subject, thereby inducing the formation of the tissue.
[0017] According to an aspect of some embodiments of the present invention there is provided
a method of treating a subject having a pathology characterized by diseased, damaged
or loss of tissue, the method comprising implanting the matrix or the hydrogel of
the invention at or near the diseased, damaged or loss tissue of the subject, thereby
inducing the formation of the tissue and treating the subject.
[0018] According to some embodiments of the invention, the polysaccharide is hyaluronic
acid.
[0019] According to some embodiments of the invention, the composition-of-matter further
comprising an antioxidant.
[0020] According to some embodiments of the invention, the antioxidant is superoxide dismutase
(SOD).
[0021] According to some embodiments of the invention, the laminin polypeptide is set forth
by SEQ ID NO:3.
[0022] According to some embodiments of the invention, the laminin polypeptide consisting
of the amino acid sequence set forth by SEQ ID NO:3.
[0023] According to some embodiments of the invention, the superoxide dismutase comprises
the amino acid sequence set forth by SEQ ID NO:4.
[0024] According to some embodiments of the invention, the composition-of-matter being cross
linked.
[0025] According to some embodiments of the invention, the polysaccharide, the antioxidant
and/or the polypeptide are cross linked.
[0026] According to some embodiments of the invention, the hyaluronic acid, the superoxide
dismutase (SOD) and the polypeptide are cross linked.
[0027] According to some embodiments of the invention, the method further comprising cross
linking the composition-of-matter.
[0028] According to some embodiments of the invention, cross-linking is effected using a
cross linking agent selected from the group consisting of EDC-N-(3-dimenthy-aminoprophyl)-N-ethyl
carbodiimide, DVS-divinyl sulfone and genipin.
[0029] According to some embodiments of the invention, the suspension comprises at least
95 % water.
[0030] According to some embodiments of the invention, the hyaluronic acid is provided at
a concentration range of about 0.5-1.5 % in the hydrogel.
[0031] According to some embodiments of the invention, the polypeptide is provided at a
concentration range of about 20-100 µg/ml in the hydrogel.
[0032] According to some embodiments of the invention, the superoxide dismutase is provided
at a concentration range of about 5-40 µg/ml in the hydrogel.
[0033] According to some embodiments of the invention, the matrix or the hydrogel further
comprising cells.
[0034] According to some embodiments of the invention, the tissue is a neural tissue. According
to some embodiments of the invention, the cells are stem cells.
[0035] According to some embodiments of the invention, the stem cells differentiate into
neuronal cells when seeded in the matrix or the hydrogel.
[0036] According to some embodiments of the invention, the hydrogel being lyophilized.
[0037] Unless otherwise defined, all technical and/or scientific terms used herein have
the same meaning as commonly understood by one of ordinary skill in the art to which
the invention pertains. Although methods and materials similar or equivalent to those
described herein can be used in the practice or testing of embodiments of the invention,
exemplary methods and/or materials are described below. In case of conflict, the patent
specification, including definitions, will control. In addition, the materials, methods,
and examples are illustrative only and are not intended to be necessarily limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Some embodiments of the invention are herein described, by way of example only, with
reference to the accompanying drawings. With specific reference now to the drawings
in detail, it is stressed that the particulars shown are by way of example and for
purposes of illustrative discussion of embodiments of the invention. In this regard,
the description taken with the drawings makes apparent to those skilled in the art
how embodiments of the invention may be practiced.
[0039] The patent or application file contains at least one drawing executed in color. Copies
of this patent or patent application publication with color drawing(s) will be provided
by the Office upon request and payment of the necessary fee.
[0040] In the drawings:
FIG. 1 is a prior art schematic illustration depicting the redox active site of a
superoxide dismutase (SOD) homologue which includes three histidine residues (His
26, 74 and 163) and an aspartic acid residue (Asp 159) surrounding the catalytic active
metal cation (copper, Cu in this case). Alternative metal cations are zinc (Zn), manganese
(Mn) and ferrous (Fe).
FIGs. 2A-F are microscopic photographs of primary cells stained with Bodian's silver
stain (Figures 2A-C) or crystal violet stain (Figures 2D-F) under various culturing
conditions. Primary fetal rat brain cells derived from cerebral hemispheres of rat
embryos (16 to 18 day of gestation) were cultured for 3 days on plastic dishes in
the presence of the Eagle's culture medium (Eagle's basal medium supplemented with
2 mM glutamine and 5 mg/ml glucose) following which the cells were either covered
with a hydrogel [1.2 % hyaluronic acid hydrogel (Figure 2B) or hyaluronic acid-superoxide
dismutase-laminin peptide (SEQ ID NO:3) hydrogel (Figures 2C-F)] or with the Eagle's
culture medium and were further cultured for additional 12 days, stained and photographed.
Figure 2A - primary cells cultured in the presence of the Eagle's culture medium stained
with Bodian's silver stain. Note the monolayers of cells and the absence of aggregates
of differentiated cells (Magnification, x 100); Figure 2B - Primary cells covered
with 1.2 % hyaluronic acid hydrogel and stained Bodian's silver stain. Note the cell
aggregates (Magnification x200); Figure 2C - Primary cells covered with the hyaluronic
acid-superoxide dismutase-laminin peptide (SEQ ID NO:3) hydrogel and stained Bodian's
silver stain. Note the differentiated neuronal cells, with typical neuronal growth,
cell associations into aggregates and conglomerates with intensive axonal sprouting
(Magnification x 200). Figures 2D-F - Primary cells grown covered with the hyaluronic
acid-superoxide dismutase-laminin peptide (SEQ ID NO:3) hydrogel and stained crystal
violet stain. Note differentiated neuronal cells with intensive axonal sprouting.
Magnifications are x 200 in Figures 2D and E and x 400 in Figure 2F.
FIG. 3 is a schematic illustration depicting the sequence of the novel laminin peptide
of the invention (SEQ ID NO:3) which is composed of the two pentapeptides (boxed sequences)
comprising the amino acid sequences set forth by SEQ ID NOs:1 and 2 (shown in red)
and 3 additional dimers: a dimer in the N-terminal position (KS), a second dimer inbetween
the two penta peptides (RS), and a third at the tail-carboxy terminal (CV).
DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION
[0041] The present invention, in some embodiments thereof, relates to compositions comprising
a novel laminin polypeptide and, more particularly, but not exclusively, to matrices
and hydrogels comprising same and methods of using same for tissue formation, regeneration
and/or repair.
[0042] Before explaining at least one embodiment of the invention in detail, it is to be
understood that the invention is not necessarily limited in its application to the
details set forth in the following description or exemplified by the Examples. The
invention is capable of other embodiments or of being practiced or carried out in
various ways.
[0043] While reducing the invention to practice, the present inventors have designed a novel
laminin polypeptide (SEQ ID NO:3) which is capable of supporting proliferation, differentiation
and/or migration of cells, such as neuronal cells. The novel laminin polypeptide includes
the two laminin penta-peptides IKVAV (SEQ ID NO:1) and YIGSR (SEQ ID NO:2) and three
dimers designed as potential sites of cross-linking: a dimer (KS) in the N-terminal
position, a second dimer (RS) inbetween the two penta peptides and a third dimmer
(CV) at the carboxy terminal.
[0044] Thus, as shown in the Examples section which follows, the present inventors have
generated a polysaccharide (hyaluronic acid) - based hydrogel which comprises the
novel laminin polypeptide and an antioxidant (superoxide dismutase). When mixed with
stem cells, the hydrogel was capable of inducing neuronal cell differentiation (Example
2, and Figures 2C-F). In contrast, hyaluronic acid-based hydrogels devoid of the novel
laminin polypeptide failed to support neuronal cell differentiation (Example 2, Figure
2B). In addition, cross-linking of the hydrogel components using Genipin did not reduce
hydrogel's abilities to support cell's proliferation and differentiation (Example
2).
[0045] Thus, according to one aspect of the invention, there is provided an isolated polypeptide
which comprises the amino acid sequence set forth by SEQ ID NO:3.
[0046] The terms "polypeptide" or "peptide" which are interchangeably used herein, encompass
native peptides (either degradation products, synthetically synthesized peptides or
recombinant peptides) and peptidomimetics (typically, synthetically synthesized peptides),
as well as peptoids and semipeptoids which are peptide analogs, which may have, for
example, modifications rendering the peptides more stable while in a body or more
capable of penetrating into cells. Such modifications include, but are not limited
to N terminus modification, C terminus modification, peptide bond modification, including,
but not limited to, CH2-NH, CH2-S, CH2-S=O, O=C-NH, CH2-O, CH2-CH2, S=C-NH, CH=CH
or CF=CH, backbone modifications, and residue modification. Methods for preparing
peptidomimetic compounds are well known in the art and are specified, for example,
in
Quantitative Drug Design, C.A. Ramsden Gd., Chapter 17.2, F. Choplin Pergamon Press
(1992), which is incorporated by reference as if fully set forth herein. Further details
in this respect are provided hereinunder.
[0047] Peptide bonds (-CO-NH-) within the peptide may be substituted, for example, by N-methylated
bonds (-N(CH3)-CO-), ester bonds (-C(R)H-C-O-O-C(R)-N-), ketomethylen bonds (-CO-CH2-),
α-aza bonds (-NH-N(R)-CO-), wherein R is any alkyl, e.g., methyl, carba bonds (-CH2-NH-),
hydroxyethylene bonds (-CH(OH)-CH2-), thioamide bonds (-CS-NH-), olefinic double bonds
(-CH=CH-), retro amide bonds (-NH-CO-), peptide derivatives (-N(R)-CH2-CO-), wherein
R is the "normal" side chain, naturally presented on the carbon atom.
[0048] These modifications can occur at any of the bonds along the peptide chain and even
at several (2-3) at the same time.
[0049] Natural aromatic amino acids, Trp, Tyr and Phe, may be substituted for synthetic
non-natural acid such as TIC, naphthylelanine (Nol), ring-methylated derivatives of
Phe, halogenated derivatives of Phe or o-methyl-Tyr.
[0050] In addition to the above, the peptides of the present invention may also include
one or more modified amino acids or one or more non-amino acid monomers (e.g. fatty
acids, complex carbohydrates etc).
[0051] The term "amino acid" or "amino acids" is understood to include the 20 naturally
occurring amino acids; those amino acids often modified post-translationally in vivo,
including, for example, hydroxyproline, phosphoserine and phosphothreonine; and other
unusual amino acids including, but not limited to, 2-aminoadipic acid, hydroxylysine,
isodesmosine, nor-valine, nor-leucine and ornithine. Furthermore, the term "amino
acid" includes both D- and L-amino acids.
[0052] Tables 1 and 2 below list naturally occurring amino acids (Table 1) and non-conventional
or modified amino acids (e.g., synthetic, Table 2) which can be used with the present
invention.
Table 1
| Amino Acid |
Three-Letter Abbreviation |
One-letter Symbol |
| alanine |
Ala |
A |
| Arginine |
Arg |
R |
| Asparagine |
Asn |
N |
| Aspartic acid |
Asp |
D |
| Cysteine |
Cys |
C |
| Glutamine |
Gln |
Q |
| Glutamic Acid |
Glu |
E |
| glycine |
Gly |
G |
| Histidine |
His |
H |
| isoleucine |
lie |
I |
| leucine |
Leu |
L |
| Lysine |
Lys |
K |
| Methionine |
Met |
M |
| phenylalanine |
Phe |
F |
| Proline |
Pro |
P |
| Serine |
Ser |
s |
| Threonine |
Thr |
T |
| tryptophan |
Trp |
w |
| tyrosine |
Tyr |
Y |
| Valine |
Val |
V |
| Any amino acid as above |
Xaa |
X |
Table 2
| Non-coventional amino acid |
Code |
Non-conventional amino acid |
Code |
| α-aminobutyric acid |
Abu |
L-N-methylalanine |
Nmala |
| α-amino-α-methylbutyrate |
Mgabu |
L-N-methylarginine |
Nmarg |
| aminocyclopropane- |
Cpro |
L-N-methylasparagine |
Nmasn |
| carboxylate |
|
L-N-methylaspartic acid |
Nmasp |
| aminoisobutyric acid |
Aib |
L-N-methylcysteine |
Nmcys |
| aminonorbornyl- |
Norb |
L-N-methylglutamine |
Nmgin |
| carboxylate |
|
L-N-methylglutamic acid |
Nmglu |
| cyclohexylalanine |
Chexa |
L-N-methythistidine |
Nmhis |
| cyclopentylalanine |
Cpen |
L-N-methylisolleucine |
Nmile |
| D-alanine |
Dal |
L-N-methylleucine |
Nmleu |
| D-arginine |
Darg |
L-N-methyllysine |
Nmlys |
| D-aspartic acid |
Dasp |
L-N-metlylmethionine |
Nmmet |
| D-cysteine |
Dcys |
L-N-methylnorleucine |
Nmnle |
| D-glutamine |
Dgln |
L-N-methylnorvaline |
Nmnva |
| D-glutamic acid |
Dglu |
L-N-methylomithine |
Nmorn |
| D-histidine |
Dhis |
L-N-methylphenylalanine |
Nmphe |
| D-isoleucine |
Dile |
L-N-methylproline |
Nmpro |
| D-leucine |
Dleu |
L-N-methylserine |
Nmser |
| D-lysine |
Dlys |
L-N-methylthreonine |
Nmthr |
| D-methionine |
Dmet |
L-N-methyltryptophan |
Nmtrp |
| D-ornithine |
Dorn |
L-N-methyltyrosine |
Nmtyr |
| D-phenylalanine |
Dphe |
L-N-methylvaline |
Nmval |
| D-proline |
Dpro |
L-N-methylethylglycine |
Nmetg |
| D-serine |
Dser |
L-N-methyl-t-butylglycine |
Nmtbug |
| D-threonine |
Dthr |
L-norleucine |
Nle |
| D-tryptophan |
Dtrp |
L-norvaline |
Nva |
| D-tyrosine |
Dtyr |
α-methyl-aminoisobutyrate |
Maib |
| D-valine |
Dval |
α-methyl-γ-aminobutyrate |
Mgabu |
| D-α-methylalanine |
Dmala |
α-methylcyclohexylalanine |
Mchexa |
| D-α-methylarginine |
Dmarg |
α-methylcyclopentylalanine |
Mcpen |
| D-α-methylasparagine |
Dmasn |
α-methyl-α-napthylalanine |
Manap |
| D-α-methylaspartate |
Dmasp |
α-methylpenicillamine |
Mpen |
| D-α-methylcysteine |
Dmcys |
N-(4-aminobutyl)glycine |
Nglu |
| D-α-methylglutamine |
Dmgln |
N-(2-aminoethyl)glycine |
Naeg |
| D-α-methylhistidine |
Dmhis |
N-(3-aminopropyl)glycine |
Norn |
| D-α-methylisoleucine |
Dmile |
N- amino-α-methylbutyrate |
Nmaabu |
| D-α-methylleucine |
Dmleu |
α-napthylalanine |
Anap |
| D-α-methyllysine |
Dmlys |
N-benzylglycine |
Nphe |
| D-α-methylmethionine |
Dmmet |
N-(2-carbamylethyl)glycine |
Ngln |
| D-α-methylomithine |
Dmom |
N-(carbamylmethyl)glycine |
Nasn |
| D-α-methylphenylalanine |
Dmphe |
N-(2-carboxyethyl)glycine |
Nglu |
| D-α-methylproline |
Dmpro |
N-(carboxymethyl)glycine |
Nasp |
| D-α-methylserine |
Dmser |
N-cyclobutylglycine |
Ncbut |
| D-α-methylthreonine |
Dmthr |
N-cycloheptylglycine |
Nchep |
| D-α-methyltryptophan |
Dmtrp |
N-cyclohexylglycine |
Nchex |
| D-α-methyhyrosine |
Dmty |
N-cyclodecylglycine |
Ncdec |
| D-α-methylvaline |
Dmval |
N-cyclododeclglycine |
Ncdod |
| D-α-methylalnine |
Dnmala |
N-cyclooctylglycine |
Ncoct |
| D-α-methylarginine |
Dnmarg |
N-cyclopropylglycine |
Ncpro |
| D-α-methylasparagine |
Dnmasn |
N-cycloundecylglycine |
Ncund |
| D-α-methylasparatate |
Dnmasp |
N-(2,2-diphenylethyl)glycine |
Nbhm |
| D-α-methylcysteine |
Dnmcys |
N-(3,3-diphenylpropyl)glycine |
Nbhe |
| D-N-methylleucine |
Dnmleu |
N-(3-indolylyethyl) glycine |
Nhtrp |
| D-N-methyllysine |
Dnmlys |
N-methyl-γ-aminobutyrate |
Nmgabu |
| N-methylcyclohexylalanine |
Nmchexa |
D-N-methylmethionine |
Dnmmet |
| D-N-methylornithine |
Dnmorn |
N-methylcyclopentylalanine |
Nmcpen |
| N-methylglycine |
Nala |
D-N-methylphenylatanine |
Dnmphe |
| N-methylaminoisobutyrate |
Nmaib |
D-N-methylproline |
Dnmpro |
| N-(1-methylpropyl)glycine |
Nile |
D-N-methylserine |
Dnmser |
| N-(2-methylpropyl)glycine |
Nile |
D-N-methylserine |
Dnmser |
| N-(2-methylpropyl)glycine |
Nleu |
D-N-methylthreonine |
Dnmthr |
| D-N-methyltryptophan |
Dnmtrp |
N-(1-methylethyl)glycine |
Nva |
| D-N-methyltyrosine |
Dnmtyr |
N-methyla-napthylalanine |
Nmanap |
| D-N-methylvaline |
Dnmval |
N-methylpenicillamine |
Nmpen |
| γ-aminobutyric acid |
Gabu |
N-(p-hydroxyphenyl)glycine |
Nhtyr |
| L-t-butylglycine |
Tbug |
N-(thiomethyl)glycine |
Ncys |
| L-ethylglycine |
Etg |
penicillamine |
Pen |
| L-homophenylalanine |
Hphe |
L-α-methylalanine |
Mala |
| L-α-methylarginine |
Marg |
L-α-methylasparagine |
Masn |
| L-α-methylaspartate |
Masp |
L-α-methyl-t-butylglycine |
Mtbug |
| L-α-methylcysteine |
Mcys |
L-methylethylglycine |
Metg |
| L-α-methylglutamine |
Mgln |
L-α-methylglutamate |
Mglu |
| L-α-methylhistidine |
Mhis |
L-α-methylhomo phenylalanine |
Mhphe |
| L-α-methylisoleucine |
Mile |
N-(2-methylthioethyl)glycine |
Nmet |
| D-N-methylglutamine |
Dnmgln |
N-(3-guanidinopropyl)glycine |
Narg |
| D-N-methylglutamate |
Dnmglu |
N-(1-hydroxyethyl)glycine |
Nthr |
| D-N-methylhistidine |
Dnmhis |
N-(hydroxyethyl)glycine |
Nser |
| D-N-methylisoleucine |
Dnmile |
N-(imidazolylethyl)giycine |
Nhis |
| D-N-methylleucine |
Dnmleu |
N-(3-indolylyethyl)glycine |
Nhtrp |
| D-N-methyllysine |
Dnmlys |
N-methyl-γ-aminobutyrate |
Nmgabu |
| N-methylcyclohexylalanine |
Nmchexa |
D-N-methylmethionine |
Dnmmet |
| D-N-methylomithine |
Dnmorn |
N-methylcyclopentylalanine |
Nmcpen |
| N-methylglycine |
Nala |
D-N-methylphenylalanine |
Dnmphe |
| N-methylaminoisobutyrate |
Nmaib |
D-N-methylproline |
Dnmpro |
| N-(1-methylpropyl)glycine |
Nile |
D-N-methylserine |
Dnmser |
| N-(2-methylpropyl)glycine |
Nleu |
D-N-methylthreonine |
Dnmthr |
| D-N-methyltryptophan |
Dnmtrp |
N-(1-methylethyl)glycine |
Nval |
| D-N-methyltyrosine |
Dnmtyr |
N-methyla-napthylalanine |
Nmanap |
| D-N-methylvaline |
Dninval |
N-methylpenicillamine |
Nmpen |
| γ-aminobutyric acid |
Gabu |
N-(p-hydroxyphenyl)glycine |
Nhtyr |
| L-t-butylglycine |
Tbug |
N-(thiomethyl)glycine |
Ncys |
| L-ethylglycine |
Etg |
penicillamine |
Pen |
| L-homophenylalanine |
Hphe |
L-α-methylalanine |
Mala |
| L-α-methylarginine |
Marg |
L-α-methylasparagine |
Masn |
| L-α-methylaspartate |
Masp |
L-α-methyl-t-butylglycine |
Mtbug |
| L-α-methylcysteine |
Mcys |
L-methylethylglycine |
Metg |
| L-α-methylglutamine |
Mgln |
L-α-methylglutamate |
Mglu |
| L-α-methylhistidine |
Mhis |
L-α-methylhomophenylalanine |
Mhphe |
| L-α-methylisoleucine |
Mile |
N-(2-methylthioethyl)glycine |
Nmet |
| L-α-methylleucine |
Mleu |
L-α-methyllysine |
Mlys |
| L-α-methylmethionine |
Mmet |
L-α-methylnorleucine |
Mnle |
| L-α-methylnorvaline |
Mnva |
L-α-methylornithine |
Morn |
| L-α-methylphenylalanine |
Mphe |
L-α-methylproline |
Mpro |
| L-α-methylserine |
mser |
L-α-methylthreonine |
Mthr |
| L-α-methylvaline |
Mtrp |
L-α-methyltyrosine |
Mtyr |
| L-α-methylleucine |
Mval Nnbhm |
L-N-methylhomophenylalanine |
Nmhphe |
| N-(N-(2,2-diphenylethyl) |
|
N-(N-(3,3-diphenylpropyl) |
|
| carbamylmethyl-glycine |
Nnbhm |
carbamylmethyl(1)glycine |
Nnbhe |
| 1-carboxy-1-(2,2-diphenyl ethylamino)cyclopropane |
Nmbc |
|
|
[0053] The peptides of the present invention are preferably utilized in a linear form, although
it will be appreciated that in cases where cyclicization does not severely interfere
with peptide characteristics, cyclic forms of the peptide can also be utilized.
[0054] Since the present peptides can be utilized in therapeutics or diagnostics which require
the peptides to be in soluble form, the peptides of the present invention preferably
include one or more non-natural or natural polar amino acids, including but not limited
to serine and threonine which are capable of increasing peptide solubility due to
their hydroxyl-containing side chain.
[0055] The peptides of the present invention may be synthesized by any techniques that are
known to those skilled in the art of peptide synthesis. For solid phase peptide synthesis,
a summary of the many techniques may be found in
J. M. Stewart and J. D. Young, Solid Phase Peptide Synthesis, W. H. Freeman Co. (San
Francisco), 1963 and
J. Meienhofer, Hormonal Proteins and Peptides, vol. 2, p. 46, Academic Press (New
York), 1973. For classical solution synthesis see
G. Schroder and K. Lupke, The Peptides, vol. 1, Academic Press (New York), 1965.
[0056] In general, these methods comprise the sequential addition of one or more amino acids
or suitably protected amino acids to a growing peptide chain. Normally, either the
amino or carboxyl group of the first amino acid is protected by a suitable protecting
group. The protected or derivatized amino acid can then either be attached to an inert
solid support or utilized in solution by adding the next amino acid in the sequence
having the complimentary (amino or carboxyl) group suitably protected, under conditions
suitable for forming the amide linkage. The protecting group is then removed from
this newly added amino acid residue and the next amino acid (suitably protected) is
then added, and so forth. After all the desired amino acids have been linked in the
proper sequence, any remaining protecting groups (and any solid support) are removed
sequentially or concurrently, to afford the final peptide compound. By simple modification
of this general procedure, it is possible to add more than one amino acid at a time
to a growing chain, for example, by coupling (under conditions which do not racemize
chiral centers) a protected tripeptide with a properly protected dipeptide to form,
after deprotection, a pentapeptide and so forth. Further description of peptide synthesis
is disclosed in
U.S. Pat. No. 6,472,505.
[0057] A preferred method of preparing the peptide compounds of the present invention involves
solid phase peptide synthesis.
[0059] In cases where large amounts or long polypeptides (e.g., longer than 20 amino acids)
are desired, the polypeptides of the present invention can be generated using recombinant
techniques such as described by
Bitter et al., (1987) Methods in Enzymol. 153:516-544,
Studier et al. (1990) Methods in Enzymol. 185:60-89,
Brisson et al. (1984) Nature 310:511-514,
Takamatsu et al. (1987) EMBO J. 6:307-311,
Coruzzi et al. (1984) EMBO J. 3:1671-1680,
Brogli et al., (1984) Science 224:838-843,
Gurley et al. (1986) Mol. Cell. Biol. 6:559-565 and
Weissbach & Weissbach, 1988, Methods for Plant Molecular Biology, Academic Press,
NY, Section VIII, pp 421-463.
[0060] Polypeptides of the present invention can be combined with a polysaccharide so as
to generate a hydrogel or a matrix.
[0061] The polysaccharide can be extracted and isolated from an organism such as a bacterium
(e.g., Pseudomonas sp NCIB 11264,
U.S. Patent No. 4298725) or can be synthetically produced by chemically reacting carbohydrate subunits (e.g.,
sugars such as glucose, glucosamine, N-Ac-glcNH
2, uronic acid or other monosaccharides or disaccharides) under suitable conditions
(see for example,
U.S. Patent No. 5,558,899). The polysaccharide may have a linear or branched structure and a molecular weight
from about 10,000 Daltons to about 3 x 10
6 Daltons.
[0062] According to some embodiments of the invention, the polysaccharide is biologically
inert having a low rate of reactivity with other substances under ordinary conditions.
[0063] According to some embodiments of the invention, the polysaccharide is biocompatible,
e.g., when in contact with cells, tissues or body fluid of an organism does not induce
adverse effects such as immunological reactions and/or rejections, cellular death,
and the like. A biocompatible polysaccharide can also be biodegradable.
[0064] According to some embodiments of the invention, the polysaccharide is capable of
forming highly hydrated gels in aqueous solutions.
[0065] Examples of suitable polysaccharides include, but are not limited to, hyaluronic
acid [e.g., sodium hyaluronate (Na-HA), Hou S, et al., 2005, J. Neurosci. Methods.
Jun 21; Epub ahead of print], alginate, agarose, chitosan, pectin, synthetic polymers
such as methylcellulose, polyglycolic acid and polylactic acid (e.g.,
Fukuhara S., et al. Circ. J. 69:850-7, 2005), hyaluronic acid (HA) hydrogels, cellulose, glycogen, starch, maltodextrin, dextran,
β-glucan, laminarin and chitin. According to some embodiments of the invention, the
polysaccharide of the invention is hyaluronic acid.
[0066] According to some embodiments of the invention, the composition-of-matter further
comprises an antioxidant which can protect cells or macromolecules (e.g., the polysaccharide)
from oxidative stress (oxidative damage caused by free radicals). Thus, the antioxidant
can extend the survival of the macromolecules by preventing their oxidative depolymerization.
[0067] Non-limiting examples of suitable antioxidants include molecules such as glutathione,
vitamin C (sodium ascorbate), vitamin E (tocopherols and tocotrienols), N-Ac-L-cysteine,
hydroquinone, glutamate, or enzymes such as catalase, superoxide dismutase, glutathione
peroxidase or other peroxidases, and glucose-6-phosphate dehydrogenase (G6PD) (see
Osmen I., Naziroglu M., Okutan R. Comparative study of antioxidant enzymes in tissues
surrounding implant in rabbits. Cell. Biochem. Funct. 24:275-281, 2006).
[0068] Superoxide dismutase, in addition to its known activity as an antioxidant, can also
serve as an anti-inflammatory agent when used
in vivo. Non-limiting examples of superoxide dismutase (SOD) enzymes which can be used in
the composition of the invention include, SOD-1 (soluble), SOD-2 (mitochondrial) or
SOD-3 (extracellular), such as homo sapiens soluble superoxide dismutase 1 (SOD-1)
GenBank Accession No. NP_000445 (SEQ ID NO:4); homo sapiens mitochondrial superoxide
dismutase 2 (SOD-2) GenBank Accession Nos. NP_001019637.1 (isoform B), NP_001019636.1
(isoform A), NP_000627.2 (isoform A); homo sapiens extracellular superoxide dismutase
3 (SOD-3) GenBank Accession No. NP_003093.2; Saccharomyces cerevisiae SOD-1 GenBank
Accession No. NP_01263 8.1; and Rattus norvegicus SOD-1 GenBank Accession No. NP_058746.
[0069] The antioxidant of the invention can be produced by recombinant techniques. For example,
a polynucleotide encoding superoxide dismutase 1 (GenBank Accession No. NM_000454;
SEQ ID NO:5) can be ligated into a nucleic acid construct suitable for expression
in a host cell (e.g., bacterial cell, yeast cell, mammalian cell). Such a nucleic
acid construct includes a promoter sequence for directing transcription of the polynucleotide
sequence in the cell in a constitutive or inducible manner, and may also include sequences
which render this vector suitable for replication and integration in prokaryotes,
eukaryotes, or preferably both (e.g., shuttle vectors); transcription and translation
initiation sequence, enhancers, transcription and translation terminator, and a polyadenylation
signal which may increase the efficiency of mRNA translation; a signal sequence for
secretion; sequences engineered to enhance stability, production, purification, yield
or toxicity of the expressed polypeptide.
[0070] The antioxidant can be recovered and purified using a variety of standard protein
purification techniques, such as, but not limited to, affinity chromatography, ion
exchange chromatography, filtration, electrophoresis, hydrophobic interaction chromatography,
gel filtration chromatography, reverse phase chromatography, concanavalin A chromatography,
chromatofocusing and differential solubilization.
[0071] According to some embodiments of the invention, the antioxidant is retrieved in "substantially
pure" form. As used herein, the phrase "substantially pure" refers to a purity that
allows for the effective use of the recombinant polypeptide as an antioxidant.
[0072] While further reducing the present invention to practice, the present inventors have
uncovered that a composition-of-matter which comprises hyaluronic acid, a laminin
polypeptide and superoxide dismutase (e.g., in a form of a hydrogel) can support neuronal
cell differentiation.
[0073] The term "laminin" as used herein refers to the family of extracellular matrix glycoproteins,
which form the major noncollagenous constituent of basement membrane. Laminins have
been implicated in a wide variety of biological processes including cell adhesion,
differentiation, migration, signaling, neurite outgrowth and metastasis. Laminins
are composed of 3 non identical chains: laminin alpha, beta and gamma, each encoded
by a distinct gene.
[0074] As used herein the phrase "laminin polypeptide" refers to an amino acid sequence
which comprises at least 4 consecutive amino acids of a laminin polypeptide and which
exhibits a biological activity (e.g., support cell growth, proliferation, differentiation
and/or migration).
[0075] According to some embodiments of the invention the laminin polypeptide can include
an amino acid sequence of a laminin alpha-chain such as LAMA1 (e.g., GenBank Accession
No. NP_005550.2), LAMA2 (e.g., GenBank Accession Nos. NP_000417.2 and NP_001073291.1),
LAMA3 (e.g., GenBank Accession Nos. NP_937762.1 and NP_000218.2), LAMA4 (e.g., GenBank
Accession Nos. NP_001098677.1, NP_001098676.1, NP_002281.2, NP_001098679.1, and NP_001098678.1),
and LAMA5 (e.g., GenBank Accession No. NP_005551.3); a laminin beta-chain such as
LAMB1 (e.g., GenBank Accession No. NP_002282.1), LAMB2 (e.g., GenBank Accession No.
NP_002283.3), LAMB3 (e.g., GenBank Accession Nos. NP_000219.2 and NP_001017402.1)
and LAMB4 (e.g., GenBank Accession No. NP_031382.2); and/or a laminin gamma-chain
such as LAMC1 (e.g., GenBank Accession No. NP_002284.3), LAMC2 (e.g., GenBank Accession
Nos. NP_005553.2 and NP_061486.2) and LAMC3 (e.g., GenBank Accession No. NP_006050.3).
[0076] According to some embodiments of the invention the laminin polypeptide includes a
repeated amino acid sequence (e.g., a 4 or 5 amino acid repeated sequence) of a laminin,
sequence.
[0077] Non-limiting examples of laminin polypeptides which can be included in the composition-of-matter
of the invention include the peptides set forth in SEQ ID NO:1, 2 or 3.
[0078] It should be noted that since the components comprised in the composition-of-matter
of the invention can be prepared using synthetic or recombinant techniques they are
obtainable as highly pure, sterile preparations of analytical or pharmaceutical grade.
[0079] As mentioned above, the present inventors have generated a hydrogel from a polysaccharide
(hyaluronic acid), an antioxidant (superoxide dismutase) and the novel laminin polypeptide
set forth by SEQ ID NO:3 (see Example 1 of the Examples section which follows).
[0080] Thus, according to an aspect of some embodiments of the invention, there is provided
a method of generating a hydrogel. The method comprising suspending the composition-of-matter
of the invention in water so as to obtain a suspension which comprises at least about
50 % water, thereby generating the hydrogel.
[0081] As used herein, the term "hydrogel" refers to a material comprising the composition-of-matter
of the invention and water, in which the water constitutes more than 50 %.
[0082] According to some embodiments of the invention, the hydrogel comprises at least about
60 % water, at least about 70 % water, at least about 80 % water, at least about 90
% water, at least about 95 % water, at least about 96 % water, at least about 97 %
water, at least about 98 % water, at least about 99 % water.
[0083] According to some embodiments of the invention, the hyaluronic acid is provided at
a concentration range of about 0.3-2 %, e.g., about 0.4-1.8 %, e.g., about 0.5-1.6,
e.g., about 0.5-1.5 %, e.g., about 0.6-1.4 %, e.g., about 0.8-1.2 %, e.g., about 1.2
% in the hydrogel.
[0084] According to some embodiments of the invention, the laminin polypeptide (e.g., SEQ
ID NO:3) is provided at a concentration range of about 10-200 µg/ml, e.g., about 20-100
µg/ml, e.g., about 50 µg/ml in the hydrogel.
[0085] According to some embodiments of the invention, superoxide dismutase is provided
at a concentration range of about 8 µM (about 0.25 microgram/ml) to 8 mM (about 250
microgram/ml) in the hydrogel. For example, superoxide dismutase can be provide at
a concentration range of about 0.5 µg/ml to about 200 µg/ml, e.g., from about 1 µg/ml
to about 100 µg/ml, e.g., from about 2 µg/ml to about 80 µg/ml, e.g., from about 4
µg/ml to about 40 µg/ml, e.g., from about 5 µg/ml to about 50 µg/ml, e.g., from about
10 µg/ml to about 50 µg/ml, e.g., from about 15 µg/ml to about 40 µg/ml, e.g., from
about 20 µg/ml to about 30 µg/ml, e.g., about 25 µ/ml.
[0086] According to some embodiments of the invention, the method further comprising cross-linking
the composition-of-matter.
[0087] Cross-linking (
i.e., binding via covalent or ionic bonds) of the components comprised in the composition-of-matter
(e.g., the polysaccharide, the antioxidant and the laminin polypeptide) can be performed
using any cross-linking or coupling agent known in the art.
[0088] Non-limiting examples of suitable cross-linking agents include dimethyl suberimidate
(an imidoester crosslinker); Bis(Sulfosuccinimidyl) suberate (BS3; an NHS-ester crosslinker);
formaldehyde; 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC; the
carbodiimide crosslinker); N-hydroxyuccinimide (NHS) [
Mao J.S, et al., Biomaterials. 24,1621-1629, 2003;
Choi Y.S., et al., J. Biomed. Mater. Res. 48,631-639, 1999;
Richert L., et al., Biomacromolecules, 5, 284-294, 2004)]; Divinyl sulfone (DVS); and genipin [
Sung H.W., et al., J Biomed. Mater. Res. A, 64A:427-438, 2003;
Chen SC., et al., J. Control Release. 96, 285-300, 2004;
Mwale F., et al., Tissue Eng., 11, 130-40, 2005;
Chen H., et al., Biomacromolecules, 7, 2091-2098, 2006].
[0089] For ex
vivo or
in vivo cross-linking photo-reactive amino acid analogs (e.g., diazirine analogs to leucine
and methionine) can be added to the composition-of-matter and following exposure to
ultraviolet light, the diazirines are activated and bind to interacting side chains
(e.g., carboxyl or amino groups).
[0090] According to some embodiments of the invention, cross-linking is performed using
a non-toxic and/or biocompatible agent. Examples include, but are not limited to 3-dimenthy-aminoprophyl)-N-ethyl
carbodiimide (EDC-N; Sigma-Aldrich- Fluka, St Louis, Missouri 63178, Catalogue No.
03459), divinyl sulfone (DVS; Sigma, Catalogue No. V-370-0) and genipin (Sigma Catalogue
No. G-4796).
[0091] According to some embodiments of the invention, the hydrogel is lyophilized by methods
well known in the art such that a dry matrix is obtained. It should be noted that
water-free matrices can be preserved for long periods of time without being subjected
to enzymatic degradation or contamination (e.g., by microorganisms).
[0092] As used herein the phrase "matrix" refers to a two-dimensional or a three-dimensional
supporting framework comprising the composition of the invention.
[0093] The matrix can be kept in a dry or wet form, or can be frozen according to the intended
use.
[0094] It should be noted that the dry matrix can be further hydrated in an aqueous solution
(e.g., water) until a hydrogel is formed.
[0095] According to some embodiments of the invention, the hydrogel or the matrix further
comprise cells (see Example 2 which follows) such as stem cells or differentiated
cells.
[0096] As used herein the phrase "stem cell" refers to cells which are capable of remaining
in an undifferentiated state (
e.g., pluripotent or multipotent stem cells) for extended periods of time in culture until
induced to differentiate into other cell types having a particular, specialized function
(
e.g., fully differentiated cells).
[0097] Non-limiting examples of stem cells which can be used by the invention include embryonic
stem cells, induced pluripotent stem cells (iPS), hematopoietic stem cells (e.g.,
bone marrow stem cells, cord blood cells, peripheral blood stem cells), adult stem
cells and mesenchymal stem cells.
[0098] Non-limiting examples of differentiated cells which can be used by the invention
include neural cells, retina cells, epidermal cells, hepatocytes, pancreatic cells,
osseous cells, cartilaginous cells, elastic cells, fibrous cells, myocytes, myocardial
cells, endothelial cells, smooth muscle cells, and hematopoietic cells (e.g., lymphocytes).
[0099] According to some embodiments of the invention, the stem cells are neuronal progenitor
cells (such as those obtained from embryonic or fetal neuronal tissue or brain).
[0100] As mentioned above and described in Example 2 (e.g., Figures 2C-F) when seeded with
stem cells derived from fetal brain, the hydrogel enabled the differentiation of the
cells to neuronal cells.
[0101] Thus, according to an aspect of some embodiments of the invention, there is provided
a method of inducing
ex vivo formation of a tissue. The method is effected by (a) providing the matrix or the
hydrogel of the invention and (ii) seeding the matrix or the hydrogel with cells in
a medium suitable for proliferation, differentiation and/or migration of the cells,
thereby inducing the formation of the tissue.
[0102] The phrase "tissue" refers to a group of cells that perform a similar function. Examples
include, but are not limited to, brain tissue, neuronal tissue, retina, skin tissue,
hepatic tissue, pancreatic tissue, bone, cartilage, connective tissue, blood tissue,
muscle tissue, cardiac tissue, vascular tissue, renal tissue, pulmonary tissue, gonadal
tissue, hematopoietic tissue. According to some embodiments of the invention, the
phrase "tissue" also encompasses an "organ",
i.e., a fully differentiated structural and functional unit in an animal that is specialized
for some particular function. Non-limiting examples of organs include head, brain,
eye, bone (e.g., of leg and hand), heart, liver kidney, lung, pancreas, ovary, testis,
and stomach.
[0103] According to some embodiments of the invention the tissue is a neural tissue.
[0104] The term "seeding" refers to plating, placing and/or dropping the cells of the within,
under or on the matrix or the hydrogel of the invention.
[0105] The concentration of the seeded cells depends on the type of cells used and the concentration
of the matrix or hydrogel's components.
[0106] The medium used according to this aspect of the invention can be any tissue culture
medium suitable for inducing the proliferation, differentiation and/or migration of
the cells (e.g., stem cells) of the invention into more specialized (i.e., differentiated)
cells. According to some embodiments of the invention the culture medium is supplemented
with minerals, amino acids and/or nutrients (e.g., Eagle's culture medium supplemented
with glutamine and glucose as described in Example 2 which follows), or further with
serum and/or growth factors.
[0107] Following seeding, the matrices or the hydrogels are routinely examined using a microscope
(e.g., an inverted microscope, an axioplan light microscope or an electronic microscope)
for evaluation of cell growth, spreading and tissue formation (see for example Figures
2A-F).
[0108] According to some embodiments of the invention, the
ex vivo formed tissue can be further implanted in a subject. In such cases the cells seeded
within the matrix or the hydrogel can be derived from the treated individual (autologous
source) or from allogeneic sources such as embryonic stem cells which are not expected
to induce an immunogenic reaction.
[0109] As used herein, the term "subject" includes both young and old human beings of both
sexes. According to some embodiments of the invention, the term encompasses individuals
who suffer from a pathology as described below.
[0110] According to an aspect of the invention there is provided a method of inducing tissue
formation
in vivo, and/or treating a subject having a pathology characterized by diseased, damaged or
loss of tissue. The method is effected by implanting the matrix or the hydrogel of
the invention in the subject, such as at or near the diseased, damaged or loss tissue
of the subject, thereby inducing the formation of the tissue and/or treating the subject.
[0111] As used herein the phrase "pathology characterized by diseased, damaged or loss of
tissue" refers to any disorder, disease or condition exhibiting a tissue damage (i.e.,
non-functioning tissue, cancerous or pre-cancerous tissue, broken tissue, fractured
tissue, fibrotic tissue, or ischemic tissue) or a tissue loss (e.g., following a trauma,
an infectious disease, a genetic disease, and the like) which require tissue regeneration.
Examples of disorders or conditions requiring tissue regeneration include, but are
not limited to, liver cirrhosis such as in hepatitis C patients (liver), Type-1 diabetes
(pancreas), cystic fibrosis (lung, liver, pancreas), bone cancer (bone), burn and
wound repair (skin), age related macular degeneration (retina), myocardial infarction,
myocardial repair, CNS lesions (myelin), articular cartilage defects (chondrocytes),
bladder degeneration, intestinal degeneration, and the like.
[0112] The phrase "treating" refers to inhibiting or arresting the development of a disease,
disorder or condition and/or causing the reduction, remission, or regression of a
disease, disorder or condition. Those of skill in the art will be aware of various
methodologies and assays which can be used to assess the development of a disease,
disorder or condition, and similarly, various methodologies and assays which can be
used to assess the reduction, remission or regression of a disease, disorder or condition.
[0114] The compositions, the matrix and/or the hydrogel of the invention may, if desired,
be presented in a pack or dispenser device, such as an FDA approved kit, or an article-of-manufacturing
(with packaging material), which may contain one or more unit dosage forms containing
the active ingredient. The pack may, for example, comprise metal or plastic foil,
such as a blister pack. The pack or dispenser device may be accompanied by instructions
for administration, implantation and/or for ex
vivo or
in vivo forming, regenerating and/or repairing a tissue and/or treating a subject. The pack
or dispenser may also be accommodated by a notice associated with the container in
a form prescribed by a governmental agency regulating the manufacture, use or sale
of pharmaceuticals, which notice is reflective of approval by the agency of the form
of the compositions or human or veterinary administration. Such notice, for example,
may be of labeling approved by the U.S. Food and Drug Administration for prescription
drugs or of an approved product insert. The compositions, matrix or hydrogel of the
invention formulated in a compatible pharmaceutical carrier may also be prepared,
placed in an appropriate container, and labeled for treatment of an indicated condition,
as is further detailed above.
[0115] As used herein the term "about" refers to ± 10 %.
[0116] The terms "comprises", "comprising", "includes", "including", "having" and their
conjugates mean "including but not limited to".
[0117] The term "consisting of means "including and limited to".
[0118] The term "consisting essentially of" means that the composition, method or structure
may include additional ingredients, steps and/or parts, but only if the additional
ingredients, steps and/or parts do not materially alter the basic and novel characteristics
of the claimed composition, method or structure.
[0119] As used herein, the singular form "a", "an" and "the" include plural references unless
the context clearly dictates otherwise. For example, the term "a compound" or "at
least one compound" may include a plurality of compounds, including mixtures thereof.
[0120] Throughout this application, various embodiments of this invention may be presented
in a range format. It should be understood that the description in range format is
merely for convenience and brevity and should not be construed as an inflexible limitation
on the scope of the invention. Accordingly, the description of a range should be considered
to have specifically disclosed all the possible subranges as well as individual numerical
values within that range. For example, description of a range such as from 1 to 6
should be considered to have specifically disclosed subranges such as from 1 to 3,
from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual
numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless
of the breadth of the range.
[0121] Whenever a numerical range is indicated herein, it is meant to include any cited
numeral (fractional or integral) within the indicated range. The phrases "ranging/ranges
between" a first indicate number and a second indicate number and "ranging/ranges
from" a first indicate number "to" a second indicate number are used herein interchangeably
and are meant to include the first and second indicated numbers and all the fractional
and integral numerals therebetween.
[0122] As used herein the term "method" refers to manners, means, techniques and procedures
for accomplishing a given task including, but not limited to, those manners, means,
techniques and procedures either known to, or readily developed from known manners,
means, techniques and procedures by practitioners of the chemical, pharmacological,
biological, biochemical and medical arts.
[0123] It is appreciated that certain features of the invention, which are, for clarity,
described in the context of separate embodiments, may also be provided in combination
in a single embodiment. Conversely, various features of the invention, which are,
for brevity, described in the context of a single embodiment, may also be provided
separately or in any suitable subcombination or as suitable in any other described
embodiment of the invention. Certain features described in the context of various
embodiments are not to be considered essential features of those embodiments, unless
the embodiment is inoperative without those elements.
[0124] Various embodiments and aspects of the present invention as delineated hereinabove
and as claimed in the claims section below find experimental support in the following
examples.
EXAMPLES
[0125] Reference is now made to the following examples, which together with the above descriptions
illustrate some embodiments of the invention in a non limiting fashion.
[0126] Generally, the nomenclature used herein and the laboratory procedures utilized in
the present invention include molecular, biochemical, microbiological and recombinant
DNA techniques. Such techniques are thoroughly explained in the literature. See, for
example, "
Molecular Cloning: A laboratory Manual" Sambrook et al., (1989); "
Current Protocols in Molecular Biology" Volumes I-III Ausubel, R. M., ed. (1994);
Ausubel et al., "Current Protocols in Molecular Biology", John Wiley and Sons, Baltimore,
Maryland (1989);
Perbal, "A Practical Guide to Molecular Cloning", John Wiley & Sons, New York (1988);
Watson et al., "Recombinant DNA", Scientific American Books, New York;
Birren et al. (eds) "Genome Analysis: A Laboratory Manual Series", Vols. 1-4, Cold
Spring Harbor Laboratory Press, New York (1998); methodologies as set forth in
U.S. Pat. Nos. 4,666,828;
4,683,202;
4,801,531;
5,192,659 and
5,272,057; "
Cell Biology: A Laboratory Handbook", Volumes I-III Cellis, J. E., ed. (1994); "
Current Protocols in Immunology" Volumes I-III Coligan J. E., ed. (1994);
Stites et al. (eds), "Basic and Clinical Immunology" (8th Edition), Appleton & Lange,
Norwalk, CT (1994);
Mishell and Shiigi (eds), "Selected Methods in Cellular Immunology", W. H. Freeman
and Co., New York (1980); available immunoassays are extensively described in the patent and scientific literature,
see, for example,
U.S. Pat. Nos. 3,791,932;
3,839,153;
3,850,752;
3,850,578;
3,853,987;
3,867,517;
3,879,262;
3,901,654;
3,935,074;
3,984,533;
3,996,345;
4,034,074;
4,098,876;
4,879,219;
5,011,771 and
5,281,521; "
Oligonucleotide Synthesis" Gait, M. J., ed. (1984); "
Nucleic Acid Hybridization" Hames, B. D., and Higgins S. J., eds. (1985); "
Transcription and Translation" Hames, B. D., and Higgins S. J., Eds. (1984); "
Animal Cell Culture" Freshney, R. I., ed. (1986); "
Immobilized Cells and Enzymes" IRL Press, (1986); "
A Practical Guide to Molecular Cloning" Perbal, B., (1984) and "
Methods in Enzymology" Vol. 1-317, Academic Press; "
PCR Protocols: A Guide To Methods And Applications", Academic Press, San Diego, CA
(1990);
Marshak et al., "Strategies for Protein Purification and Characterization - A Laboratory
Course Manual" CSHL Press (1996). Other general references are provided throughout this document. The procedures
therein are believed to be well known in the art and are provided for the convenience
of the reader.
EXAMPLE 1
GENERATION OF HYALURONIC ACID-SUPEROXIDE DISMUTASE AND A LAMININPEPTIDE HYDROGELS
[0127] Hyaluronic acid - Sodium hyaluronate is a naturally occurring high molecular weight (3 X 10
6 daltons) linear polysaccharide which is found in the extracellular matrix of connective
tissues, skin, cartilage, synovial fluids, in the vitreous humour of the eye and in
many other places. Sodium hyaluronate (Na-HA) is pharmacologically inert polymer,
forming in aqueous solutions highly hydrated gel format with viscoelastic features.
Such preparations are utilized: (1) as an opthalmological surgical aid, maintaining
eye tissue organelles intact during surgery e.g. intraocular lens insertion, intra
and extra capsular lens extraction, cataract and glaucoma surgery, corneal graft surgery,
retinal detachment and vitreal replacement procedure; (2) in joint replacement procedures
Na-HA injections serves as visco-supplementation ameliorating the inflammatory status
and inflammatory mediators, serving as an anti inflammatory agents and anti-inflammatory
mediators, serving for neutralizing free radicals and oxidative agents by its own
(HA) cleavage and depolymerising; and (iii) new avenues were open employing HA as
a friendly biomaterial, integrated in tissue engineered constructs, scaffolds gels
as cells' and tissues' supportive structures, guiding, migration and regeneration,
used as cavities filler upon tumor resection. In turn HA is easily eliminated-cleaved
by the enzyme hyaluronidase, creating empty routes for cell migration.
[0128] Superoxide dismutase - The human cytosolic Cu- Zn-SOD found in the cytoplasm of cells is a homodimer of
a molecular weight of 32,500 daltons. The two identical subunits are joined primarily
by hydropholic and electrostatic interactions. The ligands of copper and zinc are
the histidine side chains (Figure 1)
[0129] Generation of a novel laminin synthetic peptide: KSIKVAVRSYIGSRCV (SEQ ID NO:3) - The laminin peptide (SEQ ID NO:3) contains two penta peptides: the IKVAV (SEQ ID
NO:1) and YIGSR (SEQ ID NO:2) sequences, mimicking the activities of an intact laminin
molecules on neurons, and 3 additional dimers: a dimer in the N-terminal position
(KS), a second dimer inbetween the two penta peptides (RS), and a third at the tail-carboxy
terminal (CV) (See Figure 3). The dimers were placed as spacers and as potential sites
for cross linking which should therefore not interrupt the sequence of the two penta
peptides (SEQ ID NOs:1 and 2).
[0130] Cross linking agents - Cross-linking agents form covalent bonds between the three elements (Na-HA; LN peptide;
Cu-Zn-SOD) composing the hydrogel. In order to form covalent bonds without loosing
the biological activities of the bonded elements during cross linking, several cross
linking agents can be used, such as EDC-N-(3-dimenthy-aminoprophyl)-N-ethyl carbodiimide,
DVS-divinyl sulfone and genipin. Basically the principles of cross linking is combining
free primary amino groups with carboxyl groups, or oxidizing in between close hydroxyl
groups, forming reactive aldehydes, to interact either among themselves or with amines
of additional conjugate may be formed via tiol residues.
Materials and Experimental Methods
[0131] Sodium Hyaluronate - Sodium hyaluronate (HA) was produced by BioTechnology General (BTG) Corporation Ltd.
(Kiryat Weizmann, Rehovot 76326 and Be'er Tuvia, Industrial Zone, P.O. Box 571, Kiryat
Malachi, 83104 Israel) from the Streptococcus strain selected on the basis of its
high amounts of capsule secretion. It is obtained as a highly purified agent, from
the secreted capsules undergoing multi steps purification resulting in a sterile preparation
free of protein, nitrogen or pyrogen substances.
[0132] Cu, Zn Super Oxide Dismutase (Cu-Zn-SOD) - SOD [EC 1.15.1.1, soluble homo sapiens superoxide dismutase 1; GenBank Accession
No. NP_000445 (SEQ ID NO:4 for polypeptide) and GenBank Accession No. NM_000454 (SEQ
ID NO:5 for polynucleotide)] was recombinantly produced in bacteria (E. coli) by BTG
Ltd (Savient et. Ferring) essentially as described in
Hartman JR., et al., 1986 (Proc. Natl. Acad. Sci. USA, Vol: 83, pp 7142-7146)..
[0133] Synthesis of the novel laminin peptide (SEQ ID NO:3) - was performed by Elim Biopharmacenticals, Inc. Hayward, Ca. 94545, USA.
[0134] Generation of hydrogel - For the preparation of a 10 ml hydrogel, 120 mg of sodium hyaluronate (HA) was solubilized
in water for 24 hours using a magnetic stirrer, following which 50 µl of SOD (5 mg/ml)
and 500 µg of the laminin peptide (SEQ ID NO:3, as a dry powder) were added and mixed
in the hydrogel.
Analytical determinations of the elements composing the hydrogel:
[0136] Determination of Superoxide Dismutase Activity - SOD activity was measured at 560 nm as the rate of suppression of reduction of nitrotetrazolium
blue when superoxide anion radical was generated during oxidation of xanthine by xanthine
oxidase. The reaction mixture contained 50 mM sodium carbonate dissolved in 50 mM
K, Na-phosphate buffer (pH 7.8 at 25 °C), 0.1 mM EDTA, 0.1 mM xanthine, 0.025 mM nitrotetrazolium
blue. For 1 unit of activity, the amount of protein was taken which provided 50 %
inhibition of nitrotetrazolium blue reduction under standard conditions. Membrane-bound
Mn-containing SOD can be determined as the difference between total SOD activity and
that of Cu/Zn-enzyme determined after treatment of the sample with 2 % SDS Cu/Zn-SOD
was measured in cytosolic fraction of tissues and in lysates obtained from cells.
[0137] LN's active peptides determination - The penta peptides of LN are detected by specific antibodies to IKVAV (SEQ ID NO:1)
and YIGSR (SEQ ID NO:2), or an anti-laminin antibody (Sigma Cat. No. # L 9393, Sigma-Aldrich,
Israel) using immunohistochemical staining procedures.
Experimental Results
[0138] The present inventors generated a hydrogel from the following three elements: sodium
hyaluronate, a novel laminin peptide (SEQ ID NO:3) and an antioxidant (e.g., SOD).
[0139] Such a hydrogel exhibit unique physical features: (i) The hydrogel coexists with
films coating plastic surfaces e.g. fibronectin, polylysine; (ii) the hydrogel's conductivity
in isotonic salt solution (medium) is 11.0 mOhm/cm (for comparison, the conductivity
of HA alone is 1.37 mOhm/cm); (iii) the hydrogel is viscous, for example, 1 % HA,
at 100 rpm and 25 °C, 82 centipoise; (iv) the hydrogel is transparent; and (v) the
hydrogel is a slow releaser of content of added ingredients.
[0140] The hyaluronic acid-hyaluronate component (NaHA) in the hydrogel is (i) a linear,
stretched, high molecular weight, highly hydrated hyaluronic acid (HA) sodium salt.
Concentrations range between 0.5 % to 1.5 %; (ii) a polyanionic polymer formed with
only a carboxylic group at each dimmer. Other potential low reactive groups, hydroxyl
groups and N-acetylated amines; (iii) creating a hydrogel construct with a viscosity
pending in the HA concentration; (iv) a friendly milieu preserving the gaseous atmospheric
environment, and protecting the trophic added agents, at room temperature, outside
the incubator; and (v) characterizing the healthy environment in fetal life, supporting
a fast and perfect scar less wound healing.
[0141] The unique hydrogel features can be preserved for long terms as a hydrogel solution,
with slow released ingredients for weeks to 1-2 months or without ingredients, added
prior to use for longer periods; biocompatible (no inflammation mediators are evoked);
biodegradable, within the regenerative-healing period of the reparative tissue.
[0142] This hydrogel can be used to support growth, proliferation and differentiation of
various cells such as neuronal cells. The hydrogel can affect density of sprouting
axons proliferation in neuronal rich cultures, as well as in composite neuronal rich
implants transplanted
in vivo, significantly more than in cultures and implants not including such a hydrogel. Thus,
when applied on injured peripheral nerve with massive losses, an accelerated pace
of regeneration, healing and function, is expected.
[0143] The unique hydrogel developed by the present inventors simulate the extracellular
milieu, and can support cells
in vitro and
in vivo upon implantation and be used as a space cavity filler, e.g. lumens created upon
removal of neoplasmas.
[0144] The formulation of the hydrogel from the three elements HA, SOD and LN peptides (Na-HA
1.2 %; LN peptide 50 µg/ml, SOD 25 µg/ml) covalently cross linked has many defined
virtues: Extended molecular intactness of HA macromolecules due to the SOD protection
from oxidative damages of depolymerization. Both SOD molecules and high molecular
weight HA chains serve as anti-inflammatory agents, ameliorating the inflammatory
mediators status. SOD diminishes the oxidative stress conditions created in cultures
and in implanted transplantations construct
in vivo. The laminin synthetic peptide designed herein (SEQ ID NO:3) presents most of the
positive virtues of the biological activities of laminin without the disadvantages
of immunogenic reactions evoked by the whole laminin macromolecules. Furthermore,
a major source for laminin (LN-1) is its isolation from mice with Engelbreth-Holm-Swarm
ascite tumor, has a disadvantage for clinical use. The cross linked construct retaining
the full scale biological activities of its constituents, exerts a tremendous virtues,
where all the functional groups reside closely topographically together. Overcoming
the critical time periods of hostile harsh conditions in and around the implants by
the antioxidant activity of SOD and the guarding features of the LN peptides ensures
the survival of the implant, to be renourished by the diffusible nutrient starting
to arrive from the surroundings.
EXAMPLE 2
EX VIVO DIFFERENTIATION OF NEURONAL PROGENITOR CELLS INTO NEURONS WITHIN THE HYALURONIC
ACID-SUPEROXIDE DISMUTASE AND LAMININ PEPTIDE HYDROGELS
Material and Experimental Methods
[0145] Cells - Dissociated, undifferentiated stem cells derived from rat cerebral hemispheres at
16-18 days of gestation were prepared as previously described (Reshef et. al., 1996;
Reshef, A., Sperling, O., Zoref-Shan E. Preconditioning of primary rat neuronal cultures
against ischemic injury: characterization of the 'time window of protection. Brain
Res. 741, 252-257, 1996). The cells were maintained on plastic dishes with Eagle's culture medium [Eagle's
basal medium containing Earle's salts (Sigma, St. Louis, MO) supplemented with 2 mM
glutamine and 5 mg/ml glucose (Biological Industries, Kibbuts Beit Haemek, Israel)]
in a 95 % air and 5 % CO
2, in a humidified atmosphere, at 37 °C. For testing the various culture conditions,
the cells were cultured on the plastic dishes in the presence of the Eagle's for 3
days without changing the medium, following which the medium was changed and the cells
were further cultured for additional 12 days on the plastic dishes in the presence
of the medium (control, culture conditions "i") or were covered with various hydrogels
(culture conditions "ii", "iii" and "iv") as follows:
Culture conditions
[0146]
- (i) Control cultures included cells cultured in the presence of Eagle's culture medium and maintained
on plastic dishes;
- (ii) Hyaluronic acid hydrogel cultures - 1.2 % hyaluronic acid was added to the attached cells at the third day post seeding;
- (iii) Hyaluronic acid - laminin peptide - antioxidant hydrogel cultures - on the third day in culture the cells were cultured in the presence of mixed hyaluronic
acid (1.2 %), a synthetic peptide of laminin (50 µg/ml) made of 16 amino acids (SEQ
ID NO:3; KSIKVAVRSYIGSRCV) and an antioxidant (Cu- Zn superoxide dismutase (Cu-Zn
- SOD, 25 µg/ml).
- (iv) Cross-linked hyaluronic acid - laminin peptide - antioxidant hydrogel cultures - on the third day in culture the cells were cultured in the presence of cross-linked
hyaluronic acid (1.2 %), a synthetic peptide of laminin (50 µg/ml) made of 16 amino
acids (SEQ ID NO:3; KSIKVAVRSYIGSRCV) and an antioxidant (Cu- Zn superoxide dismutase
(Cu-Zn - SOD, 25 µg/ml). The cross linker agent used in most experiments was Genipin,
although other cross linking agents such as Carbodiimide, divinyl sulfone or just
sugars (monosaccharides) have been successfully employed as a cross linker. Nissl staining procedure for neurons - Crystal violet 0.1 % (0.1 gram in 100 ml distilled water plus 10 drops of glacial
acetic acid, filtering just before use). The stain detects Nissl bodies in the cytoplasm
of neurons in cultures or tissue sections fixed in formalin and embedded in paraffin.
The Nissl bodies are stained purple-blue to pink-violet. Additional neuron's specific
staining procedures: Bodian's silver method described in Pearse (1972; Pearse, A. Histochemistry, Theoretical and Applied. Vols 1 & 2, 3rd edition, Little,
Brown & Co, Boston, MA, 1972); immunohistochemical procedures: anti MAP-2; anti GAP-43, or anti neurospecific
enolase are used further to assess the differentiating neurons.
Experimental Results
[0147] As shown in Figure 2A, control cultures maintained on plastic dishes, exhibited the
growth of a non-confluent monolayered cultures. In contrast, in cultures growing in
the presence of 1.2 % hyaluronic acid hydrogel the cells tend to form cell aggregates
(conglomerates) (Figure 2B). The third type of cultures included cells growing in
the presence of a hydrogel containing hyaluronic acid (1.2 %), the synthetic laminin
peptide (SEQ ID NO:3; 50 µg/ml) and the Cu- Zn superoxide dismutase (Cu-Zn - SOD,
25 µg/ml) antioxidant. As shown in Figures 2C-F, cells grown with a hydrogel containing
hyaluronic acid, laminin peptide (SEQ ID NO:3) and the Cu- Zn superoxide dismutase
formed cell aggregates accompanied with intensive dendrite sprouting, simulating mature
functional neurons.
[0148] It should be noted that primary cells cultured in hydrogels which included mixed
constituents (culture iii) or cross-linked constituents (culture iv) were not significantly
different from each other (data not shown). Thus, to prevent possible dissertation
of the small molecular weight constituents (e.g. the laminin peptide and/or SOD) out
of the hydrogel, the hydrogels can be cross-linked without loosing their intrinsic
characteristics and ability to support proliferation, differentiation and migration
of cells.
[0149] Hydrogels which included hyaluronic acid, SOD and the laminin synthetic peptide (SEQ
ID NO:3) which serves as a guiding growth factor, drive the cells cultured therein
towards differentiation, e.g., neurogenesis, while superoxide dismutase serves as
a neuroprotectant agent.
[0150] Further treatment of the aggregates by, e.g., subculturing the cells after trypsinization,
is expected to release and spread out migrating neurons. Such cultures growing in
the presence of the hydrogel containing hyaluronic acid, laminin peptide (SEQ ID NO:3)
and the Cu- Zn superoxide dismutase can be utilized as 3D constructs for further transplantation,
regeneration into injured, degenerated or missing neuronal elements
in vivo, readily adjusted with dense fibers for implantation into damaged peripheral nerves
tissue.
[0151] As a collaborative work with Prof. Eyal Zusmann from the Technion, Israel, a polycaprolactone
(PCL) tube of 2 mm in diameter was used as a bridge for a massive region loss, connecting
the two stumps of the torn peripheral nerve. The tubes were filled with a hydrogel
containing hyaluronic acid (1.2 %), the synthetic laminin peptide (SEQ ID NO:3; 50
µg/ml) and Cu- Zn superoxide dismutase (Cu-Zn - SOD, 25 microgram/ml), versus control
of naked tubes. A higher density of neuronal sprouting was observed in one out of
two injured rats, demonstrating a complete and perfect bridging of 2 cm region loss.
These studies demonstrate the use of the hydrogel of some embodiments of the invention
for neuronal tissue regeneration and repair.
[0152] Although the invention has been described in conjunction with specific embodiments
thereof, it is evident that many alternatives, modifications and variations will be
apparent to those skilled in the art. Accordingly, it is intended to embrace all such
alternatives, modifications and variations that fall within the scope of the appended
claims.
[0153] In addition, citation or identification of any reference in this application shall
not be construed as an admission that such reference is available as prior art to
the present invention. To the extent that section headings are used, they should not
be construed as necessarily limiting.
REFERENCES
(Additional references are cited in text)
[0154]
Coviello T., Matricardi P., Marianecci C., Alhaique F. Polysaccharide hydrogels for
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Hallmann R., Horn N., Selg M., Wendler O., Pausch F., Sorokin L.M. Expression and
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2005.
Hartman JR., 1986., Proc. Natl. Acad. Sci. 83: 7142-7146.
Ho M.H., Wang D.M., Hsieh H.J., Liu H.C., Hsien T.Y., Lai J.Y., Hou L.T. Preparation
and characterization of RGD-immobilized chitosan scaffolds. Biomaterials. 26, 3197-3206,
2005.
Hou S., Xu Q., Tian W., Cui F., Cai Q., Ma J., Lee I.S. The repair of brain by implantation
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2005.
Itoh S., Matsuda A., Kobayashi H., Ichinose S., Shinomiya K., Tanaka J. Effects of
a laminin peptide (YIGSR) immobilized on crab-tendon chitosan tubes on nerve regeneration.
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Powell S.K., Kleinman H.K. Neuronal laminins and their cellular receptors. Int. J.
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Sekurai K., Miyazaki K., Kodera Y., Nishimura H., Shingu M., Inada Y. Anti-inflammatory
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Suzuki M., Itoh S., Yamaguchi I., Takakuda K., Kobayashi H., Shinomiya K., Tanaka
J. Tendon chitosan tubes covalently coupled with synthesized laminin peptides facilitate
nerve regeneration in vivo. J Neurosci. Res.72, 646-659, 2003.
Tashiro K., Sephel G.C., Weeks B., Sasaki M., Martin G.R., Kleinman H.K., Yamada Y.
A synthetic peptide containing the IKVAV sequence from the A chain of laminin mediates
cell attachment, migration, and neurite outgrowth. J Biol Chem. 264, 16174-16182,
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Yamazaki K., Fukuda K., Matsukawa M., Hara F., Matsushita T., Yamamoto N., Yoshida
K., Munakata H., Hamanishi C. Cyclic tensile stretch loaded on bovine chondrocytes
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SEQUENCE LISTING
[0155]
<110> Ramot At Tel Aviv University Ltd. Medical Research Fund of Tel Aviv Sourasky
Medical Center Rochkind, Shimon Nevo, Zvi
<120> POLYPEPTIDES, MATRICES, HYDROGELS AND METHODS OF USING SAME FOR TISSUE REGENERATION
AND REPAIR
<130> 42215
<150> US 60/935,487
<151> 2007-08-15
<160> 5
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